Gear Production Research Articles

Material Removal Rate of Face-Milled Bevel Gears Based on a Ring-Dexel Cutting Simulation

Abstract Face milling is not only a primary machining technique for the mass production of bevel gears, but it has also become a standardized process integrated into computer numerical control (CNC) bevel gear-cutting machines in the last two decades. Controlling suitable feed rates for face milling is one of the most direct and pivotal factors influencing processing efficiency for CNC machines. Despite being programmed through numerical codes, the feed rates provided by the gear machines most rely on experiential insights rather than optimization. Therefore, leveraging material removal rate (MRR) directly correlates with machining power and will hold immense potential for optimizing feed rates and enhancing efficiency. Because commercial software solutions cannot accurately predict the MRR for face milling operations, this paper uses a novel ring-dexel-based model for cutting simulation to address this issue. The main aim of this model is to provide a more precise prediction of the MRR across all face milling cuttings. By controlling the cutting depth and generating angle, the ring gear's plunging process and the pinion's single-roll generating process were successfully simulated. Thus, the MRRs through all cutting processes were calculated. Experimental results showed that tool torques are positively correlated with the MRRs. Finally, by appropriately increasing the cutting feed rate based on the MRR, the pinion and ring gear machining times were reduced by 44% and 18%, respectively.

Innovations in Engineering and Technology of Worm-Type Gears

Relatively small changes in engineering and technology of traditional established products turn over time into a series of milestones that determine both technical characteristics and production methods, and as a consequence - the competitiveness of the final product. Accordingly, it is relevant to periodically look at the evolution of the accumulated solutions and make some conclusions on it. For this purpose, the paper reviews innovations in design and production of worm-type gears obtained in Izhevsk scientific school in the field of gears for the last two decades: spiroid gears operating at low rotational speeds and transmitting high loads, leading to plastic deformations due to compactness of gears; spiroid gears with small gear ratios (3...8) competing with more expensive in production bevel and hypoid ones; worm gears with steel hardened gearwheels with increased strength and manufacturability; planetary spiroid gears providing extremely high gear ratio, improved methods and techniques of design and preproduction of gear cutting. The paper presents the review of innovations in design of worm-type gears made in Izhevsk scientific school in the field of gears for the last two decades: spiroid gears for cases of low speeds and small gear ratios, worm gears with steel hardened gearwheels, planetary and spiroid gears, improved methods and techniques of design and preparation of gear cutting.

The Concept of Technological Support of Operational Properties Based on Stabilization of Mechanical Properties of Gear Materials in a Gas Turbine Engine Drive System

Modern production of gears for gas turbine engines for aviation, marine and land use is inherently related to the calculation of the stress state of the working surfaces of the mating teeth. To create conditions for the operability of the gear train and the drive system as a whole, an engineering analysis of the contact endurance of the mating surfaces is a necessary criterion. The contact strength determines the life of the gear mechanism. The value of the contact strength, taking into account its distribution in the contact zone of the working mating surfaces of the gears, is determined by the processing technology and operation, but the mechanical properties and texture of the material have the greatest influence. This determines the requirements for the stability of the mechanical properties of the materials used for the manufacture of gears, making a topical question on their study. The technology of manufacturing the gears in the gas turbine engine drives forms the layer structure of the toothed crown because of the use of chemical-thermal treatment. The surface hardened layer of the gear tooth after chemical-thermal treatment is saturated with carbon and nitrogen, and as a result of thermal action acquires mechanical properties and structure different from the material in the supply. The paper presents the results of practical research of evolution of mechanical properties of structural steels 20H3MVF-Sh, 18H2N4MA, 16H3NVFM-Sh and 12H2N4A-Sh based on various types of chemical-thermal treatment, as well as microstructure of toughened layer and core of the part. The steel mechanical properties stabilization evaluation in the process of gear technology was performed. The presented results of experimental studies of mechanical properties of the material prove stabilization of mechanical and structural indicators, which are responsible for the contact strength of the mating surfaces of toothed gears.

Effect of the brass waste recycling process on mechanical properties with investment casting for gear materials

This study is an experimental research to analyze the characteristics and mechanical properties of the casting process of recycled brass alloy, which will be used as a material for gears. Currently, the remaining production and waste from brass alloys continue to increase. Another thing is the increase in the need for brass gears, so environmentally friendly material engineering is needed to provide good quality and efficient energy use, especially during the casting process. The casting process uses an electric furnace that melts brass alloys at 526 up to 900 °C within 1 hour and molds to make test specimens. The results of microstructural testing for grain size in recycled brass alloys range from 74.63 μm to 84.57 μm. The maximum tensile strength produced is up to 225.2 MPa, the maximum yield strength is up to 179.8 MPa, and the maximum elongation is up to 7.3 %. The roughness of recycled brass alloys has a maximum Ra value (average roughness) of up to 0.836 μm. Validation was carried out by comparing the mechanical properties of CAC 302 brass products and the study results. The data shows that recycled brass's maximum yield strength value is 179.8 MPa and CAC 302 brass material is 175 MPa, but for the ultimate tensile strength value, the value of recycled brass is far below CAC 302 products. These results can be a consideration for the industry to be able to use recycled brass alloys for gear products because the yield strength value is not far from CAC 302 brass products. The impact result of this study produces recycled brass alloys that are environmentally friendly, efficient in smelting energy consumption, and have good yield strength. The results of this research can benefit the manufacture of gear components made of brass alloys.

Dry Grinding: A More Sustainable Manufacturing Process for the Production of Automotive Gears

Dry Grinding: A More Sustainable Manufacturing Process for the Production of Automotive Gears

A Novel Multi-Objective Dynamic Reliability Optimization Approach for a Planetary Gear Transmission Mechanism

Planetary gear transmission mechanisms (PGTMs) are widely used in mechanical transmission systems due to their compact structure and high transmission efficiency. To implement the reliability design and optimization of a PGTM, a novel multi-objective dynamic reliability optimization approach is proposed. First, a multi-objective reliability optimization model is established. Furthermore, considering the strength degradation of gears during service, a dynamic reliability analysis is conducted based on the theory of nonlinear fatigue damage accumulation. In addition, to improve computing efficiency, a random forest surrogate model based on the particle swarm optimization algorithm is proposed. Finally, an adaptive multi-objective evolutionary algorithm based on decomposition (AMOEA/D) is designed to optimize the mechanism, along with an adaptive neighborhood updating strategy and a hybrid crossover operator. The feasibility and superiority of the proposed approach are verified through an NGW planetary gear reducer. The results show that the proposed surrogate model can reduce the calculation cost and has high accuracy. The AMOEA/D algorithm can improve transmission efficiency, reduce gear volume and ensure reliability at the same time. It can provide guidance for actual gear production.

Intelligent Inspection Method and System of Plastic Gear Surface Defects Based on Adaptive Sample Weighting Deep Learning Model.

After injection molding, plastic gears often exhibit surface defects, including those on end faces and tooth surfaces. These defects encompass a wide range of types and possess complex characteristics, which pose challenges for inspection. Current visual inspection systems for plastic gears suffer from limitations such as single-category defect inspection and low accuracy. There is an urgent industry need for a comprehensive and accurate method and system for inspecting defects on plastic gears, with improved inspection capability and higher accuracy. This paper presents an intelligent inspection algorithm network for plastic gear defects (PGD-net), which effectively captures subtle defect features at arbitrary locations on the surface compared to other models. An adaptive sample weighting method is proposed and integrated into an improved Focal-IoU loss function to address the issue of low inspection accuracy caused by imbalanced defect dataset distributions, thus enhancing the regression accuracy for difficult defect categories. CoordConv layers are incorporated into each inspection head to improve the model's generalization capability. Furthermore, a dataset of plastic gear surface defects comprising 16 types of defects is constructed, and our algorithm is trained and tested on this dataset. The PGD-net achieves a comprehensive mean average precision (mAP) value of 95.6% for the 16 defect types. Additionally, an online inspection system is developed based on the PGD-net algorithm, which can be integrated with plastic gear production lines to achieve online full inspection and automatic sorting of plastic gear defects. The entire system has been successfully applied in plastic gear production lines, conducting daily inspections of over 60,000 gears.

Gear Hobs-Cutting Tools and Manufacturing Technologies for Spur Gears: The State of the Art.

The present work aims to provide the readers with a bird's-eye view of the general domain of cylindrical gear manufacturing technologies, including the cutting tools used, and related topics. The main scientific sources are explored to collect data about the subject. A systematization of the scientific works is completed, to emphasize the main issues the researchers have focused on in the past years in the domain. Several specific aspects are investigated: chip-forming process, cutting tool lifetime, the materials used to produce gear hobs, temperature and lubrication, the cutting tool geometry, cutting parameters, design methods, and optimization. Some gaps in the research have been identified, which are mainly related to the gear hob's design. These gaps, the organization of knowledge, the current requirements of the industry, and the actual socio-economic priorities form the basis for identifying new scientific research directions for the future in the area of spur gears manufacturing technologies and cutting tools. The main output of this work is a frame to guide the development of scientific research in the domain of spur gear production.

Perhitungan Ongkos Pemesinan Konvensional Menggunakan Macro Vba Excel pada Studi Kasus (Produk Roda Gigi Payung Ø65mm × Z24)

In the conventional machining process, production costs are essential to know to determine the cost of making a product in any industrial manufacturing such as the SMK N 2 PEKANBARU machining workshop. Machining production costs are calculated based on machining time per product and machining operation costs. In calculating conventional machining costs, the VBA Excel macro is an application that can be used to calculate production costs. The Ø65mm × z24 umbrella gear product which is the research case study is a product that is machined by two conventional machining processes, namely lathe machining and milling machining. From the results of the research, the cost of conventional lathe machining, namely making gear wheels, is IDR 47,841/product, and the conventional milling process, namely making Z24 gears, is IDR 40,002/product, while the machining cost for lathe mastercam simulation is IDR 33,187/product and the machining cost for milling mastercam simulation is IDR 20,340/product. Machining costs are the product of operating costs per minute (cm) and machining time (tm). So, from the results of calculating machining and production costs, it is known that the product manufacturing costs or production costs for Ø65mm × Z24 umbrella gears are in the range of IDR 111,827 - IDR 146,143/product.

Multiobjective Optimization of Hard Turning on OHNS Steel Using Desirability and TOPSIS Approaches

Machining hard materials with 45–48 HRC is difficult in turning operation because of the improvident cutting parameter selections for the operation. The OHNS (AISI/SAE-01–48HRC) steel is mainly preferred for the production of shafts, gears, cams, and press tools. The OHNS material was turned at a dry state using VP-coated carbide inserts. The seventeen experimental trials were designed by central composite design (CCD) with different levels of cutting parameters, like feed rate, cutting speed, and depth of cut. Design Expert-11 software desirability approach and TOPSIS (Technique for Order Preference by Simulating the Ideal Solution) were used to analyse the experimental results to obtain a single optimal solution that defines better results on metal removal rate (MRR) and surface finish (Ra). RSM solution with 81.3% desirability, the cutting speed of 60 m/min, feed rate of 0.08 mm/rev, and depth of cut 1 mm as the optimal cutting parameters; similarly, TOPSIS algorithm calculation identifies the cutting parameter combinations, such as 40 m/min cutting speed, 0.09 mm/rev feed rate, and 1 mm depth cut to enrich the quality of the machined steel; however, the desirability approach cutting parameter setting is better for the surface finish achievement, while TOPSIS solution is better to obtain significant MRR. The confirmation test results validated for the predicted values of both approaches; as such, the experimental results were maintained better convenience than the predicted one. For the optimum cutting parameter combinations, an MRR of 22.032 gm/min and surface roughness of 0.781 μm were obtained at 60 m/min cutting speed, 0.08 mm/rev feed rate, and 1 mm depth of cut.

Mesh Characteristic Analysis of Spiral Bevel Gear Pairs Considering Assembly Errors and Tooth Tip Chipping Faults

Due to machining errors, location inaccuracies, human error, and various other factors, it is challenging to avoid assembly errors during the production of spiral bevel gears (SBGs). When SBG assembly errors occur, it can cause the appearance of edge contact and may even lead to severe tooth tip chipping. In this study, we propose an improved method based on loaded tooth contact analysis (LTCA) to examine mesh characteristics, including time-varying mesh stiffness (TVMS), unloaded transmission error, and contact stress. Furthermore, we explore the effects of assembly errors and tooth tip chipping. Moreover, it is observed that assembly errors can alter the contact area of SBGs and potentially reduce the peak-to-peak value of TVMS. Additionally, the occurrence of tooth tip chipping decreases TVMS within the chipping region, lowers transmission error, and increases maximum contact stress. Notably, when assembly errors are present, the reduction in TVMS due to tooth tip chipping exceeds that of a properly assembled SBG pair.

Эластичные хоны для полирования профилей зубьев термообработанных цилиндрических колес специального назначения

Introduction. The most important component of the technological process of manufacturing of gear wheels of critical products is the operation of teeth honing. Special requirements are imposed on the surface quality of special-purpose gears, where imported abrasive tools were used, the supply of which in modern economic conditions is impossible. Purpose of work: development of formulation, technological equipment and technology of manufacturing of elastic diamond gear hones instead of imported ones for teeth honing of gear wheels of special purpose. Research methods. Subject of research are samples of imported elastic gear hones and created domestic analogs. The mechanical properties, morphology and chemical composition of the abrasive (diamond) layer of the working surface of the teeth and the annular gear were determined. The content of chemical elements was controlled in separate points of the surface and by scanning over the area on a scanning electron microscope. The formulation and technology of production of annular gears were determined. Results and Discussion. Designs of molds for forming the abrasive layer and the hub of the gear hone are developed. The peculiarities of morphology of the material of the working layer and the annular gear of the elastic diamond gear hone are revealed. On the basis of the conducted research, domestic analogs of materials of constituent elements of the gear hone are determined. Two manufacturing technologies were considered: pressing and injection molding. Two molds were made to test the technology: a simplified model consisting of two teeth and a round mold. Several methods of manufacturing hone teeth were analyzed: manufacturing of an abrasive layer with different degree of pre-vulcanization, subsequent introduction of gear material and final vulcanization of the whole product. The mechanical properties of the materials of the working abrasive layer and the annular gear were determined. The chemical composition of the components of the hone and the boundary zone are studied. As a result of the conducted research, recommendations on the formulation of the abrasive layer and the annular gear, technology of manufacturing of the gear hone intended for final treatment of teeth of heat-treated spur wheels of special purpose are given.

Experimental investigation on the surface quality of WEDM machined 20MnCr5 steel for gear application

This experimental study investigates the Wire-cut Electrical Discharge Machining (WEDM) of 20MnCr5 steel, a low alloy steel grade material which is intended for the production of gears, shafts and other parts which need high surface hardness and wear resistance. WEDM is a crucial manufacturing process for producing gears, shafts, spindles, and various mechanical components. The investigation focuses on three key performance parameters: profile error, material removal rate (MRR), and surface roughness (SR), employing five WEDM parameters—wire feed (Wf), wire tension (Wt), servo voltage (SV), discharge arc-off time (Toff), and arc-on time (Ton) - by employing the Taguchi L27 orthogonal array. The study reveals that, in comparison to arc-on time and servo voltage, wire feed rate and tension have a lesser impact. Higher arc-on time and servo voltage result in increased profile error, while reduced wire tension values elevate surface roughness. Recast layer formation has been explored under different WEDM input parameters, revealing its dependence on arc-on time, voltage, wire tension, and feed rate. Higher voltage leads to uneven surfaces with larger globules and deep craters, contributing to a thicker recast layer at higher arc-on time and servo voltage.

Silicon Nanoparticles Derived from Waste Rice Husk as Potential Siliconizing Material for Mild Steel

Siliconizing is one of the case-hardening processes used in the enhancement of some carbon-steel based material properties. Gears, rolling engineering parts, and pickling tanks produced with mild steel can offer better wear and hot-corrosion resistance characteristics through siliconizing. However, the cost of silicon hindered the wide usage of siliconized mild steel, which is the motivation for seeking remedy through processing of agro-waste materials. In this work, waste rice husk was used in the production of silicon nanoparticles using the sol-gel method. The silicon nanoparticles produced were used in the siliconizing of mild steel. The microstructure, hardness values, wear and corrosion tests were determined. The work shows that enhanced hardness values with improved corrosion and wear resistance were obtained when using waste rice husk to siliconize mild steel that can be used in the production of gears and storage tanks.

Research on the Hobbing Processing Method of Marine Beveloid Gear

Due to the particular structure of the beveloid gear, it cannot be directly hobbed by an ordinary gear hobbing machine. The existing processing method is complex and has a high cost. Therefore, the mass production and industrialization of beveloid gears are limited. To improve the machining efficiency and accuracy of processing beveloid gears, we proposed a hobbing method via the modification of ordinary hobbing machines. At first, we completed the derivation and calculation of the relevant processing parameters of the beveloid gear based on the study of the structural characteristics of the beveloid gear and the principle of hobbing machining. Then, we proposed and designed a beveloid gear hobbing method, and the modification of the ordinary hobbing machine was completed by using a hanging wheel mechanism in synchronous belt type. Finally, we completed the actual hobbing of the beveloid gear, and the feasibility of the proposed method was verified. After that, we analyzed the machining error of the trial-produced beveloid gear; the results showed that the accuracy of the trial-produced beveloid gear met the 6-level standard, which also verified the accuracy of the proposed method.

Calculation of the producing surfaces of milling cutters for processing gears of eccentric-cycloidal engagement

The paper considers a new method for processing curved gears of eccentric-cycloidal engagement with a curved profile using a special tool. The surfaces of wheels of eccentric-cycloidal engagement with a curved profile for small and large wheels are simulated. The scheme of forming a small wheel of eccentric-cycloidal engagement using a shaped milling cutter with a constructive radial feed is shown. The producing surface of the milling cutter is obtained, which allows to fulfill all the conditions of shaping when implementing the proposed scheme for shaping a small wheel of eccentric-cycloidal engagement with a curved profile. For a large wheel, a shaping scheme using the rolling method using a worm wheel is proposed. Modeling of the producing surface of a worm mill for shaping the surface of a large wheel of eccentric-cycloidal engagement using the rolling method is performed. This approach can be used in the design of milling cutters designed for processing curved gears of eccentric-cycloidal engagement of various sizes. The use of such tools will make it possible to make the transition to serial and mass production of gears with this engagement.

Sustainability-oriented dry cutting tool collaborative optimization model for face-hobbing hypoid gears

Dry cutting as an important sustainability manufacturing technology is enhancing ever-higher levels of hypoid gear production. To improve economic and environmental attributes of sustainability manufacturing, a new data-driven dry cutting tool collaborative optimization model considering both geometric accuracy and loaded contact performances is established for face-hobbing hypoid gears. Where, an innovative ease-off tooth contact analysis (e-TCA) method is proposed to establish accurate relations between ease-off flank and loaded contact performance evaluations. Then, for the initial design flank from arc-shaped tool, Top-Rem tool modification is applied to establish the collaborative optimization model. By fine-modifying the ease-off flank relating to Top-Rem tool parameters, the current design flank can get an adaptive approximation to the target flank requiring the loaded contact performance evaluations. Moreover, in addition to the accuracy and efficiency of dry cutting at its own, the cutting gear number of per hour, cutting gear number of per tool and cutting power consumption are used the main assessment items on sustainability. The numerical and experimental examples are provided to verify that the proposed tool collaborative optimization model will significantly improve sustainability in terms of economic and environmental assessments.

PROFIL PERIKANAN PANCING TONDA DEMERSAL DI PERAIRAN SELAT SAPE, KABUPATEN BIMA NUSA TENGGARA BARAT

The potential of fisheries resources in the Indonesian sea consists of four fishery resources, namely: large pelagic (451,830 tons per year) and small pelagic (2,423,000 tons per year), demersal fisheries resources (3,163,630 tons per year), shrimp (100,720 tons per year) per tofu) and reef fish (80,082 tons per year). This study aims to determine the catch using demersal trolling in the Sape Strait and to determine the biological status of fish caught by using a troll demersa fishing rod To determine the biological status of fish caught using demersal trolling rods. This research will be carried out in the waters of the Sape Strait of West Nusa Tenggara. Data collection methods used in this study are descriptive, quantitative and qualitative methods. These methods describe in detail all the activities carried out during the research activities, so that they are able to answer the problems or goals that have been set. The results of this study were processed using Fisheries Biology Analysis such as length and weight relationship pattern analysis, growth pattern analysis of the condition of the feasibility of the fishing gear analysis of fishing gear productivity effectiveness of fishing gear environmental friendliness analysis of the gear sensitivity of the fishing gear business feasibility analysis

Tooth root stress reduction of plastic gears with biological inspired shape optimization

The geometry of plastic gears used today is usually based on conventional steel gears, which are bound to the restrictions of the machining production of gears. The injection molding process provides more design freedom. This paper presents an approach to reduce the tooth root stress of plastic gears using a biologically inspired shape optimization method called CAO (Computer-Aided Optimization). CAO imitates the biological growth behavior from nature, such as bones or trees, which adapt to the load. It strengthens more heavily loaded areas of the surface and weakens less heavily loaded areas, resulting in an increase in load-bearing capacity. The simulation method is based on finite element analysis and considers the complex material behavior of short fiber reinforced plastics as well as the inhomogeneous fiber orientation. Object of the study are polymer gears made of polyamide 46 with and without short fiber reinforcement. By using the method presented here, it is possible to reduce the tooth root stress by up to 24% compared to a trochoidal tooth root with maximum rounding.

Gear skiving with minimum twist errors

Over the last 15 years, gear skiving has established itself as a highly productive gear cutting process for the production of internal gears and gears with near interference contours. As with all processes with crossed axes, gear skiving generally results in a pronounced natural twist when gears with lead crowning or other flank modifications are produced. In practical applications, the unintended profile angle changes over the tooth width resulting from the twist leading to unwanted contact patterns and unfavorable NVH behavior. In this work, a contact line-based method for tool profile calculation for gear skiving is developed based on conical-screw gear theory. The relationship between contact line and natural twist errors is worked out. The process and tool design strategies for minimizing the twist are elaborated and finally, an adaptive process kinematics for low-twist error gear skiving is presented.